Tuning Air Venturi Avenger - Barrel Stiffening

[revenger]

You are

I'm confused... Higher velocity = faster spin on the projectile. If it performed well at lower velocity your twist rate would be good at any velocity an air rifle can produce. A faster twist rate is to stabilize longer projectiles than your current twist rate is capable of. Higher velocity usually helps stabilize a projectile that needs more spin. A 220 swift powder burner can make 50 grain varmint bullets disintegrate from centrifugal force before they reach the target if you push them too fast.

You are right. However, the speeds I can reach to achieve max FPE (over 120) require large slugs that are exceptionally long like boat tails. So the speeds that I can reach are not fast enough to stabilize them properly even though I'm achieving a high energy number for a .25 PCP. Only way to combat it is to fire at same speed with a faster twist rate. So while you are correct, it's just that we can't fire these projectiles at fast enough speed to stabilize. I confirmed all of this with bullet stabilization calculators. Pushing "heavy grain" projectiles that a long, require much faster rates for proper stabilization at subsonic speeds.